Reginald W. Bennett

U.S. Food and Drug Administration | FDA · Office of Regulatory Science and Innovation

Novel staphylococcal enterotoxins (SEs) expressed by Staphylococcus aureus strains have been described throughout the years, among these being the SE protein SER. To further characterize this toxin, this research used 13 S. aureus strains previously determined to contain the SE type R (ser) gene. These S. aureus isolates were evaluated using serolo...

Nine different food products frequently associated with Bacillus cereus outbreaks were chosen as representative matrices to be evaluated with end‐point polymerase chain reaction (PCR), enzyme linked immunosorbent assay, lateral flow device and mass spectrometry for detection of enterotoxins associated with human illness. Testing was performed on fo...

Lipids are soluble in organic solvents and staphylococcal enterotoxins are water‐soluble. This recognized feature can assist in the recovery of these toxins. Partitioning studies were conducted using a toxin‐insoluble organic solvent ( CHCl 3 ) treatment for the extraction of toxins from the lipid portion of the tested food products. Enterotoxin se...

Aims: The aim of this study was to evaluate the performance of immunodetection methods and PCR analysis of enterotoxigenic Bacillus cereus strains. Methods and results: Eighty-eight enterotoxigenic B. cereus group strains linked to food-borne outbreaks and illnesses were studied with 30 exclusivity nonenterotoxigenic strains including Bacillus a...

Staphylococcus aureus continues to play a significant role in foodborne outbreak investigations, with numerous individuals sickened each year after ingesting assorted foods contaminated with staphylococcal enterotoxins. The purpose of this study was to evaluate the use of several methods for the screening, detection, and enterotoxin serotyping of s...

Aims: The study objective was to characterize and analyse the distribution of enterotoxins and genes encoding enterotoxins in Staphylococcus aureus strains recovered from the 601 environment and ingredient samples obtained during multiple inspections of a bakery implicated in two separate staphylococcal food poisoning incidents. Methods and resul...

Guam school children and faculty members experienced symptoms of vomiting, nausea, abdominal cramps, and diarrhea shortly after eating breakfast prepared by contracted caterers. The first illness was reported within an hour after breakfast, affecting 295 students and two faculty members. Local hospitals treated 130 people, and 61 were admitted for...

The first time Staphylococcus aureus was associated with foodborne illness dates back as early as 1884 when spherical organisms in cheese caused a large food-poisoning outbreak in the United States. The growth and proliferation of Staphylococcus aureus in foods present a potential hazard to consumer health since many strains of S. aureus produce en...

Over 100 individuals were sickened after ingesting an assortment of desserts linked to four staphylococcal food poisoning outbreaks leading investigators to products manufactured by an Illinois bakery. The investigative team identified substantial deviations from the current Good Manufacturing Practice Regulations, 21 CFR Part 110, during multiple...

Bacillus cereus is a group of ubiquitous facultative anaerobic sporeforming Gram-positive rods commonly found in soil. The spores frequently contaminate a variety of foods, including produce, meat, eggs, and dairy products. Foodborne illnesses associated with toxins produced by B. cereus can result in self-limiting diarrhea or vomiting. Plate enume...

Raw whole liquid and dried eggs which were purported to contain staphylococcal enterotoxin were analyzed by a number of enzyme-linked immunosorbent assay (ELISA)-based methods. The initial evaluation was to establish whether the purported positive ELISA reactions were a result of toxin-anti-enterotoxin serological activity. A secondary consideratio...

Studies were conducted with an automated enzyme-linked immunosorbent assay (ELISA)-based method (Vidas, Staph enterotoxin-II [SET-II]), exhibiting an antibody capture that had undergone modification by removal of the Fc fragment on the antibody. Raw liquid or shell eggs containing a nontoxin component with an attraction to the staphylococcal antien...

The effect of two sodium phosphate-sodium chloride buffers (0.2 M, pH 7.4 and 0.05 M, pH 6.5) on the separation of staphylococcal enterotoxins from soluble proteins in foods was examined by ion exchange column chromatography. The microslide gel diffusion test, by which recovery was determined, was more accurately interpreted when lower ionic streng...

Staphylococcal enterotoxins A (SEA) and D (SED) were added to infant formula and to cream of celery soup to determine the persistence of their serological and biological activities during simulated commercial canning. When both food products were retorted at 123.9°C with Fo values of approximately 3 and 8, the enterotoxins were reduced or inactivat...

The problem of Staphylococcus aureus and other species as contaminants in the food supply remains significant on a global level. Time and temperature abuse of a food product contaminated with enterotoxigenic staphylococci can result in formation of enterotoxin, which can produce foodborne illness when the product is ingested. Between 100 and 200 ng...

The problem of Staphylococcus aureus and other species as contaminants in the food supply remains significant on a global level. Time and temperature abuse of a food product contaminated with enterotoxigenic staphylococci can result in formation of enterotoxin, which can produce foodborne illness when the product is ingested. Between 100 and 200 ng...

The microbial quality of five types of fresh produce obtained at the retail level was determined by standard quantitative techniques. These techniques included aerobic plate count (APC), total coliform counts, Escherichia coli counts, and yeast and mold counts. Three different methods were used to determine total coliform counts, which consisted of...

Staphylococcal food poisoning is a commonly reported illness caused by the ingestion of preformed staphylococcal enterotoxin in foods. With some exceptions, enterotoxin production is associated with coagulase-positive rather than coagulase-negative staphylococci. Of the coagulase-positive staphylococcal species, S. aureus was historically thought t...

From February through April 1989, four outbreaks of staphylococcal food poisoning in the United States were associated with eating mushrooms canned in the People's Republic of China (PRC). In the four outbreaks, 99 persons who ate at a suspect facility developed gastrointestinal symptoms within 24 h, including 18 who were hospitalized. Illness was...

There has been a great deal of recent interest in parallel I/O. We discuss the design and implementation of the Jovian library, which is intended to optimize the I/O performance of multiprocessor architectures that include multiple disks or disk arrays. We also present preliminary performance measurements from benchmarking the Jovian I/O library on...

An outbreak of food intoxication involving over 265 cases in western United States occurred in October 1991. Staphylococcus intermedius was implicated as the aetiologic agent. Representative outbreak isolates (five clinical and ten from foods) produced type A enterotoxin. DNA fragments generated by four restriction endonucleases and analysed by pul...

Fourteen strains of Bacillus cereus isolated from different sources were examined for their ability to produce diarrhoeal enterotoxin by two commercial immunoassay kits (Oxoid BCET-RPLA and Tecra ELISA) and the microslide immunodiffusion assay. One strain that was positive in monkey feedings, as well as a number of other strains isolated from diarr...

Fourteen strains of Bacillus cereus isolated from different sources were examined for their ability to produce diarrhoeal enterotoxin by two commercial immunoassay kits (Oxoid BCET-RPLA and Tecra ELISA) and the microslide immunodiffusion assay. One strain that was positive in monkey feedings, as well as a number of other strains isolated from diarr...

Selected foods containing 4-10 ng each of a mixture of Staphylococcus aureus enterotoxin serotypes A-E were tested by 15 collaborators. An enzyme-linked immunosorbent assay (EIA) was used with polyvalent antisera to these serotypes in a polyclonal antibody double "sandwich" configuration. Controls were free of toxin. Foods (25 g test samples) were...

Physical processes in hydrocarbon flames are highly complex and interact in a strongly non-linear fashion. Numerical experimentation is an excellent way to isolate physical processes, study their interactions, or predict important properties such as flammability limits. Only highly detailed models that include complex chemistry and diffusive proces...

Although Bacillus cereus was long considered to be a harmless saprophite, its role as a food poisoning organism has been known since the 1950s (Goepfert et al., 1972; Hauge, 1955). Consumption of foods containing millions of B. cereus cells per gram frequently results in food poisoning. Two types of illness have been attributed to consumption of fo...

This chapter presents monoclonal antibodies (MAbs) to the enterotoxins and to the toxic shock syndrome toxin produced by Staphylococcus aureus. Staphylococcus aureus is an important opportunistic pathogen common to humans and many other warm-blooded animals. It is the etiological agent in a variety of pathological conditions ranging from common ski...

A monoclonal antibody capable of binding to determinants shared in common by staphylococcal enterotoxin serotypes A, B, C1, D, and E was developed. To accomplish this, BALB/c mice were immunized by alternating injections of serotypes A and D to enrich for spleen lymphocytes programmed to produce antibody to possible common determinants. These cells...

The ability of eleven imitation (or substitute) cheeses to support the growth and toxin production of Staphylococcus aureus at 26°C was evaluated. All established enterotoxin serotypes were tested by inoculating suspensions of the requisite strains into 100-g samples of cheese (about 30 staphylococci/g). Water activity (aw) of the cheese samples ra...

Size-exclusion, ion-exchange, and reversed-phase chromatography were investigated for use in purification and characterization of Staphylococcal enterotoxin B (SEB), a 28,000 Mr protein associated with Staphylococcal food-borne intoxication. In all approaches chromatography of crude or purified SEB yielded one or more components which displayed tox...

Plastic-enclosed sausage, hamburger and turkey sandwiches were inoculated with enterotoxigenic Staphylococcus aureus to evaluate the potential hazard of staphylococcal food poisoning in sealed foods maintained in an N2 environment. The effect of such food storage on staphylococcal growth and enterotoxin production was determined under varying condi...

A study was performed by 15 collaborators on a method for the extraction and chromatographic separation of Staphylococcus aureus enterotoxins from foods. Enterotoxin types A--E were added to crabmeat, milk, ground beef, and potato. Evaluation of the method was based on solubility of food eluates after extraction and separation of the enterotoxin; e...

A study was performed by 15 collaborators on a method for the extraction and chromatographic separation of Staphylococcus aureus enterotoxins from foods. Enterotoxin types A–E were added to crabmeat, milk, ground beef, and potato. Evaluation of the method was based on solubility of food eluates after extraction and separation of the enterotoxin; ef...

A collaborative study was conducted, using the microslide gel double diffusion test for enterotoxin detection by determining the staphylococcal enterotoxigenicity of 7 strains of Staphylococcus aureus. Two strains produced staphylococcal enterotoxin A (SEA), 2 strains produced staphylococcal enterotoxin B (SEB), one strain produced both SEA and SEB...

A rapid solid-phase radioimmunoassay for staphylococcal enterotoxin A is described. The assay procedure requires 3 to 4 h for completion by using a competitive inhibition system in which the antibody is attached to bromacetyl cellulose particles. It is accurate to a level of 0.01 mug of enterotoxin A/ml in a variety of media such as ham, milk produ...

A rapid solid-phase radioimmunoassay for staphylococcal enterotoxin A is described. The assay procedure requires 3 to 4 h for completion by using a competitive inhibition system in which the antibody is attached to bromacetyl cellulose particles. It is accurate to a level of 0.01 μg of enterotoxin A/ml in a variety of media such as ham, milk produc...

The high specificity of the microslide gel diffusion test far outweighs the more sensitive, but less specific, agglutination procedures for the detection of the serologically identifiable staphylococcal enterotoxins. The results of collaborative and interlaboratory studies during the past 2 years on the detection and identification of staphylococca...

A fourth staphylococcal enterotoxin was identified serologically with antiserum to the very crude enterotoxic products of growth of a strain which also produces enterotoxin C, and then with antiserum to the considerably purified enterotoxic antigen of a strain which produces only the new enterotoxin. The identification of this antigen as enterotoxi...

Methods are described for the extraction and serological detection of trace amounts of enterotoxins A and B in foods incriminated in outbreaks of staphylococcal food poisoning. Evidence is presented for the probable applicability of the methods for the detection of unidentified enterotoxins.

Methods are described for the extraction and serological detection of trace amounts of enterotoxins A and B in foods incriminated in outbreaks of staphylococcal food poisoning. Evidence is presented for the probable applicability of the methods for the detection of unidentified enterotoxins.

Immunization of rabbits with approximately 95% pure enterotoxin B and approximately 20 and 50% pure enterotoxin A yielded specific antisera which required no and little absorption, respectively, when used in the slide double-diffusion test. Methods for purifying enterotoxin A and for the production and absorption of antisera are presented.

Immunization of rabbits with approximately 95% pure enterotoxin B and approximately 20 and 50% pure enterotoxin A yielded specific antisera which required no and little absorption, respectively, when used in the slide double-diffusion test. Methods for purifying enterotoxin A and for the production and absorption of antisera are presented.

Casman, E. P. (U.S. Food and Drug Administration, Washington, D.C.) and R. W. Bennett. Culture medium for the production of staphylococcal Enterotoxin A. J. Bacteriol. 86 18–23. 1963.—By use of Wadsworth's modification of the gel diffusion test of Ouchterlony for the assay of enterotoxin, cultivation on semisolid Brain Heart Infusion Agar of pH 5....